Sheet handling mechanism



Sept. 1, 1942. s. A. HUFFMAN SHEET HANDLING MECHANISM Original Filed March 31, 1938 '7 sheets -sheet l INVENTOR g famue/AZ fluff/773D Q-WALQ.

7 Sheets-Sheet 2 INVENTOR Sept. 1, 1942. s. A. HUFFMAN I SHEET HANDLING MECHANISM Original Filed March 31, 1938 Sept..l, 1942. s. A. HUFFMAN 2,294,406

SHEET HANDLING MECHANISM Original Filed March 51, 195a 7 Sheets-Sheet 5 Fig. 4.

INVENTOR Samue/ ,4. Huff/77a idqpww ZZZ s. A. HUFFMAN 2,294,406

SHEET HANDLING MECHANISM Sept. 1, 1942.

Original Filed March 31, 1938 7 Sheets-Sheet 4 W 1942 s. A. HUFFMAN 2,294,4fi6

SHEET HANDLING MECHANISM Original Filed March 31, 1938 '7 Sheets-Sheet 5 INVENTOR famue/A Huffman Sept. 1, 1942. s. A. HUFFMAN SHEET HANDLING MECHANISM Original Filed March 51, 1938 7 Sheets-Sheet 6 R INVENTOR Sept. 1, 1942. 5A. HUFFMAN SHEET HANDLING MECHANISM Original Filed March 31, 1938 7 Sheets-Sheet 7 INVENTOR Samuel AHufF-man Patented Sept. 1, 1942 SHEET HANDLING MECHANISM Samuel A. Huffman, Avalon, Pa., assignor to Miller Printing Machinery 00., Pittsburgh, Pa., a corporation of Pennsylvania Original application March 31, 1938, Serial No.

Divided and this application Septemher 9, 1939, Serial No. 294,166

26 Claims.

division of my copending application Serial No.

199,167; another division thereof is my copending application Serial No. 299,309.

- The problem of handling sheets is encountered in various industrial operations. The best known of such applications is the feeding of sheets to a printing press and the delivery of sheets therefrom. This invention is particularly adapted to such application and will be described with special reference to the feeding of sheets to a printing press, although the invention is not limited to this application but has other uses as well.

Sheet handling mechanisms for printing presses have heretofore included reciprocating members of considerable mass. Any attempt to operate such equipment at high speed introduces objectionable stress, shock and vibration. It is an object of the invention, therefore, to improve generally on sheet handling mechanisms as known heretofore, and particularly to avoid reciprocating parts to a large degree, thus permitting high speed operation without the aforementioned objectionable stress, shock and vibration. In accordance with the invention I employ endless belts for advancing sheets successively. The belts travel over a suitably formed table or other support and I provide vacuum means for progressively holding a sheet in contact with the travelling belts. The application of vacuum to the sheet at each point in its path of travel is controlled automatically to insure the desired movement without crumpling or other injury to the sheet.

The invention may take numerous different forms, and the following detailed description will cover only a few of the numerous possibilities. The forms of the invention to be described herein with reference to the accompanying drawings are sheet handling mechanisms adapted to feed sheet-s singly from a pile to a press. Several modified forms will be described. In the drawings:

Fig. 1 is a plan view of a conveyor mechanism for feeding sheets singly from a stock pile to the cylinder of a press of the-flat bed and cylinder yp Fig. 2 is a side elevation thereof;

Fig. 3 is a view partly in section and partly in elevation to an enlarged scale illustrating certain of the details shown in Figs. 1 and 2;

Fig. 4 is a plan view of a modified form of conveyor for feeding sheets from a pile to a press cylinder;

Fig. 5 is a side elevation thereof;

Fig. 6 is a diagrammatic view of a further form of sheet feeder;

Fig. '7 is a similar view of a still further form of feeder;

Fig. 8 is a fragmentary elevational view showing the driving means for the perforated belt and for the vacuum control valve;

Fig. 9 is an elevation of the stator of a rotary valve employed to control the vacuum applied progressively to the sheets for holding them in contact with the conveyor belt;

Fig. 10 is a sectional view through the stator and rotor of the valve along the line X--X of Fig. 9;

Fig. 11 is an elevation of the rotor of the valve;

Fig. 12 is a view similar to Fig. 8 showing a constant speed drive for the tapes 225; and

Fig. 13 is a view similar to Fig. 7 of a similar structure.

Figs. 1 through 3 illustrate the application of the vacuum belt conveyor to the feeding of sheets successively from a pile. The illustrated embodiment of the invention is designed for feeding sheets to the cylinder of a press C but it may be employed with equal facility for feeding sheets to other processing machines. The feeder conveyor shown in Figs. 1 through 3 comprises a feed board 220 having vacuum ports 22! spaced therealong. The feed board extends from frame members 222, on which a pile support 223 is mounted for vertical movement, to a point adjacent the cylinder of the press C, being secured to the side frames thereof as at 224.

A perforated belt 225 is trained over guide sheaves 226 journaled in the feed board, a driving sheave 22! mounted on a shaft 228 and a belt tightener 229. The shaft 228 is journaled in side arms 23!! and 23l to which' the, feed board 220 is secured. The tightener sheave 229 is mounted on links 232 pivoted to the side flanges of the feed board. The side arms 23!! and 23l are pivoted on a shaft 233 extending between frame members 222, and the whole conveyor mechanism may be tilted about the shaft.

The shaft 228 is driven by a pulley 234 through a clutch 235. The pulley 234 is carried on a-shaft 236 journaled in a bearing bracket 231. Cooperating clutch members on the shafts 228 and 236 are normally urged into engagement by a spring 238. A clutch releasing bar 239 is slidlably mounted in the side arms 230 and 23L The pulley 234 is driven at a variable speed screwed into tapped holes in the stator 14 by mechanism shown in Figs. 1, z and 8. A pulley I93 is journaled on a bearing bracket I94 dependent'from a portion I56 of the side frame. A crank I95 is journaled on a shaft I96 extending laterally from the side frame portion I56 and has a slide I91 thereon and which reciprocates a block I96. A crank I99 carried by the pulley I93 has a pivotal connection with the block I98. The crank I95 is driven from the shaft "I by a chain and sprocket drive 200.

It will be apparent that the elements just described cause the pulley I93 to move at maximum angular-velocity when the throw of the crank I95 is a maximum, i. e., when the crank extends substantially. upward. Similarly, the

pulley I93 moves at its minimum angular velocity when the crank I95 extends downwardly. The variation in the speed of the pulley I93 is caused by the eccentricity between its axis and that of the crank I95.

A belt I8I extends about the pulleys 234 and I93 and constitutes (the means whereby the former is driven from the latter. By means of the mechanism just described the belt I6I is driven at variable speed and the parts of the drive mechanism are so dimensioned and arranged that the belt 225 travels at its minimum speed when the vacuum is applied to the port nearest the cylinder of the press in a manner presently to be described. By this means a sheet advanced by the belt 225 is decelerated almost to a standstill on approaching the drop guides.

In order to cause the belt 225 to advance a sheet delivered thereto over the feed board 220 from a pile indicated at 250 toward the cylinder of the press 0, I provide means for applying vacuum progressively to the ports 22L Because of the perforations 22511 in the belt 225 the vacuum applied to the ports 22I causes a sheet delivered to the board 220 to be held against the belt 225 by atmospheric pressure. I provide a rotary valve for controlling the application of vacuum to the ports 22I in a manner such that the point at which vacuum isappliecl at any instant will coincide substantially with the position of the leading edge of a sheet moving along the board at that instant. The valve is shown in Figs. 9 through 11 and is indicated and 2 by the numeral 240. The valve comprises a stator 14 and a rotor 15. The stator has feet 16 whereby it is secured to pads formed on the side of the board 228. The stator has a tapered bore and the rotor is correspondingly shaped for cooperation therewith. Ports 11 are spaced circumferentially of the bore through the stator. A

speed of the cylinder of Hose connections 16 extend between fittings and generally in Figs. 1-

port it will beapplied to the next succeeding port. Continuous traction of the belt 225 on the advancing sheet is thus assured.

The rotor 15 is keyed to a shaft 82 having a flange 83 engaging a bearing surface 94 on the stator 14. The shaft 82 carries a sprocket 86 driven through a sprocket chain I 80 by a sprocket 86a on the shaft I". A- clutch 2 for controlling the operation of the valve is normally maintained in engagement by a spring 242. A releasing bar 243 for the clutch 24I is slidably mounted in the side arms 230 and 23I. Hold-down tapes 244 are trained about guide and tightening sheaves 245 and a driving sheave 246. The latter is driven by a belt 241 trained about a pulley 248 on the shaft 228 and a pulley 249 on the shaft on which sheave 246 is mounted.

Sheets are fed successively from the pile 256 by suction feet 25I. The feet 25I are carried on supporting rods 252 depending from arms 253.

The arms 253 are pivoted to cranks 254 secured to a cross shaft 255. This shaft is oscillated by a push rod 256 and a crank 251. The push rod may be reciprocated by any convenient means in timed relation with the operation of the press.

The arms 253 have pins 258 at their rear ends fitting into arcuate slots 259 in guide plates 268. The plates 260 are secured to a cross bar 26| and are journaled on, the shaft 255. By reason of this construction, it will be apparent that the shoes 25I move from the position shown in solid lines in Fig. 3 to the position shown in dotted lines and vice versa, on oscillation of the shaft 255. Vacuum is applied to the feet 25I by suitable hose connections (not shown). The pile support 223 is raised automatically to maintain the top sheet at an elevation such that it will be engaged by the shoes 25I. The shoes are thus effective to engage the leading edge of the top sheet on the pile and advance the sheet to a position such that its leading edge is subject to the vacuum applied to the first port 22I on the feed board. The degree of vacuum applied to the shoes and the port can be so controlled that when the sheet has been caused to engage the belt it readily departs from the shoes. After the sheet has been engaged by the belt it is advanced along the feed board in a manner which will be clear from what has been said.

The invention thus provides conveying means for delivering a sheet from a pile to a position the board 220, communicating respectively with the ports 11 and the ports 22I. port 19 formed in the stator 14 is similarly connected to a vacuum pump (not shown).

An annular groove 80 is formed in the rotor 15 and is so positioned axially thereof as to overlie the port 19. A recess 8| formed in the rotor communicates with the groove 80 and is adapted successively to overlie the ports 11 on rotation of the rotor. By this means the ports 22I are successively connected to the vacuum pump as the recess 8| passes over the ports 11 to which the ports 22I are connected. As shown in Fig. 11, the recess 8| is wide enough to overlie two adjacent ports 11 simultaneously. This insures that at least one of the ports 22l will have vacuum applied thereto at all times, or, in other words, that before vacuum is cut off from one A main vacuum in which it is accurately registered relatively to the cylinder of a press. The speed of the delivery board conveyor belt may be substantially the same as or greater or less than the peripheral press C. The sheet is held in contact with the traction belt 225 as it travels along the delivery board. The hold-down tapes prevent the edges of the sheet from being lifted by the resistance of the air. The speed of the hold-down tapes is substantially the same as that of the belt 225. The speed of this belt is variable. It is so driven as to accelerate the sheet slightly and then decelerate it almost to a standstill as it approaches the drop guides. The conveyor does not actually stop but continues to urge this sheet against the drop guides while side registry takes place. After accurate registry the grippers on the cylinder of the press C engage the leading edge of the sheet for the printing operation. If desired the belt 225 may be driven at a substantially constant speed. This may, for example, be done asshown in Fig. 12, in which the shaft Ill carries a pulley "Ia and a belt !8!a passes about the pulley Illa and the pulley 234.

The rotary valve 248 maintains the application of vacuum to the belt 225 at the point where the leading rdge of the sheet engages the latter to insure positive feeding without slippage.

The feeder conveyor is provided with side registry means including a shaft 262 reciprocable axially in lateral extensions 263 from the side arms 230 and 23!. A bell crank 264 pivoted on the side arm 23!] has a pin and slot connection with the shaft 262. A link 265 connects the bell crank 264 with a bell crank 266 pivoted on the side arm 230. A push rod 26'! reciprocated by any convenient means in timed relation with the operation of the press is connected to the bell crank 266 by a link 268.

It will be seen from the foregoing description that the invention may be embodied in a conveyor for feeding sheets from a pile to a machine such as a printing press wherein they are individually processed. As each sheet is engaged by the traction belt, it is accelerated for rapid feeding movement and then decelerated almost to a standstill for front and side registry.

Figs. 4 and 5 show a modification of the structure shown in Figs. 1 through 3 in which the traction belt is disposed above the feed board. This is desirable for feeding certain types'of sheets such as cardboard. The structure of Figs. 4 and 5 is quite similar to that of Figs. 1 through 3, and corresponding parts will be designated by the same reference numerals, the principal difference being that the former is provided with a vacuum plate 215 disposed above the feed board 220 and supported on cross bars 216 carried in the side arms 23!] and 23!. A traction belt 21! is trained over guide sheaves 218 at the ends of the plate 215 and around tightener and driving sheaves 219 and 28!]. The tightener sheave 219 is journaled on arms 28! pivoted to the side arms 230 and 23!. The sheave 28!] is mounted on a shaft 282 corresponding to the shaft 228 of Fig. 1. Hold-down tapes (not shown) may be provided as in the form of the invention already described. Since the conveyor belt is mounted above the feed board inthe structure shown in Figs. land 5, it is unnecessary to provide any hold-down tapes.

Sheets are fed to the belt 21! from a pil 283 by suction feet 284. The latter are carried on supporting rods 285 depending from cranks 286 keyed to a cross shaft 281. The latter is journaled in the frame members 222. how the frame members 222 are hinged to the press frame at 288.

The shaft 281 is oscillated by a crank 288 to which a push rod 290 is pivoted. The push rod 290 is reciprocated by any convenient means. It will be evident that reciprocation of the push rod causes vertical reciprocation of the feet 284. The latter are effective to lift the top sheet from the pile 283 into engagement with the belt 211. The Vacuum applied to the ports 29! formed in the plate 215 by the valve 240 causes the sheet to be seized by the belt 21'! and fed down the board 220.

The operation of the feeder conveyor shown in Figs. 4 and 5 is substantially the same as that of the conveyor of Figs. 1 through 3. It will be understood that the traction belt 21! is driven at a variable speed in the same manner as the belt 225. The driving shaft 236 of the modification shown in Figs. 4 and 5 is journaled in a Fig. 5 shows I cylinder 362.

bearing standard 292 which also carries the drive shaft for the valve 240.

Fig. 6 is a diagrammatic showing of a modified form of feeder utilizing the principle of the invention. In this figure, as in Fig. 7 to be described later, parts are shown diagrammatically which have already been illustrated in detail. Fig. 6 shows a conveyor belt 360 adapted to feed sheets singly from a pile 36! to a press The conveyor 360 may be a perforated traction belt traversing a feed board having vacuum ports therein or may be simply a plain endless belt. The pile 360 is stacked against bars 363 and is elevated as sheets are fed therefrom. Suction feet 364 are movable from the solid line to the dotted line position and back. An air jet is directed across the top of the pile by nozzles 365. The belt 360 is driven at a substantially constant speed which is considerably less than the peripheral speed of the cylinder 362.

The operation of the mechanism shown in Fig. 6 is as follows:

The suction feet 364 operate intermittently to lift the trailing end of the top sheet on the pile 36!. When the trailing edge of the top sheet is lifted, the nozzles 35 blow air under the forward portion of the sheet and cause it to rise above the ends of the bars 363. The forward movement of the shoes 364 permits the leading edge of the sheet to be engaged by the conveyor belt 368. After the sheet has been engaged by the belt, it is pulled away from the shoes 364 and advanced toward the cylinder. The mech-- anism may be so designed and constructed that one sheet will be lifted from the pile and advanced to the conveyor before the trailing edge of the preceding sheet has cleared the bars 363. As a result, a plurality of sheets may be disposed in overlapped relation on the conveyor belt 360 at all times. By reason of this arrangement, the cylinder can be operated at high speed since each succeeding sheet has to travel only a relatively short distance to engage the drop guides and be positioned for engagement by the cylinder grippers.

Fig. 7 shows an arrangement similar to that of Fig. 6 except that the feeding of sheets from the pile 36! to the cylinder 362 is effected jointly by a plain conveyor belt 368 and a vacuum belt 36'! similar to the perforated traction belts previously described. The operation of the mechanism of Fig. 7 is substantially the same as that of apparatus of Fig. 6. Fig. 13 shows a similar structure in which the dotted position of the suction feet 364 corresponds to the dotted position in Fig. 6.

Although I have illustrated and described herein certain present preferred forms of the invention, it will be understood that changes in the construction and operation disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Apparatus for successively conveying sheets from a pile thereof to a processing machine such as a press comprising a traction belt, means for driving said belt toward said machine whereby a sheet delivered to the belt is first accelerated and then decelerated after engaging the belt and fed toward the machine, and means for arresting said sheet in a predetermined position relative to said machine, said last mentioned means being effective to arrest the sheet while the belt continues to be driven toward the machine.

sheet from the pile, a nozzle for operating with the second 2. Apparatus for successively conveying sheets from a. pile thereof to a processing machine such as a press comprising a traction belt, means for driving said belt toward said machine whereby a sheetdelivered to the belt is first accelerated andthen decelerated thereby and moved toward said machine, and means for arresting'said sheet in a predetermined position relative to said machine, said last mentioned means being effective to arrest the sheet while the belt continues to be driven toward the machine.

3. Apparatus for successively conveying sheets and means for holding the remainder of the comprising moving articles sequentially from the from a pile thereof to a processing machine such as a press comprising a traction belt, and means for lifting the trailing edge of the top sheet from the pile, a nozzle for directing a fluid jet on said sheet to cause the leading edge thereof to rise into engagement with said belt, said belt being driven at variable speed so that a sheet engaging the belt is accelerated and fed toward said machine, and registers for arresting said sheet in a predetermined position relative to said machine. 4. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press, comprising a traction belt operable toward the cylinder at a speed less than the peripheral speed of the cylinder, and means for causing sheets successively to engage the belt singly in non-overlapping relation.

5. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press, comprising a traction belt operable toward the cylinder at a speed less than the peripheral speed of the cylinder, means for causing sheets to engage the belt singly, and vacuum means for causing the sheet to adhere to said belt.

6. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press, comprising a traction belt, a second traction belt above that first mentioned and extending over said pile, means for lifting the trailing edge of the top directing a, jet toward said sheet to cause the leading edge thereof to engage said second belt, said belts being driven at the same speed, and vacuum means cooperating with the second belt to cause a sheet to adhere thereto.

7. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press, comprising a traction belt, a second traction belt above that first mentioned and extending over said pile, means for lifting the trailing edge of the top sheet from the pile, a nozzle for directing a jet toward said sheet to cause the leading edge there- I of to engage said second belt, said belts being driven at the same speed, vacuum means cobelt to cause a sheet to adhere thereto, and means for holding the remainder of the sheets in the pile against forward movement.

l 8. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press, comprising a traction belt, means adjacent the rear of said pile for separating -the uppermost sheet therefrom and carrying it forward and means adapted to engage the sheet and advance it to said belt.

9. Apparatus forconveying sheets singly from a pile thereof to the cylinder of a press, comprising a tractionbelt, means adjacent the rear of said pile for separating the uppermost sheet therefrom and carrying it forward, means adapted to engage the sheet top of a pile of such articles and after such movement of each article moving it forward and without altering the sequence of movement of the articles first accelerating and then decelerating the movement of each article and regulating such movement 50 that the article reaches a predeter mined position while it continues, even after reaching such position, to be still urged forward but at minimum speed.

12. In the art of feeding sheets from a pile to a position in which they are in registry with the drop guides of a press cylinder, the steps comprising moving sheets sequentially fron the top of the pile and after such movement of each sheet moving it forward and without altering the sequence of movement of the sheets first accelerating and then decelerating the movement of each sheet and regulating such movement so that the sheet reaches registry with the drop guides of the press cylinder while it continues, even after reaching registry, to be still urged for ward but at minimum speed.

13. In the art of feeding sheets, delivering a sheet from rest to a moving conveyor, maintaining the sheet in place on the conveyor by suction and changing the speed of movement of the conveyor and feeding the sheet from the conveyor to mechanism for operating upon the same at a speed different from the speed of movement of the conveyor at the time of delivery of the'sheet thereto.

14. In the feeding of sheets as to a press or the like, maintaining a sheet against a carrier by.

vacuum applied only in the zone of the longitudinal center line of the sheet, advancing the carrier with the sheet so maintained thereagainst and while so advancing the carrier with the sheet maintained thereagainst registering the sheet to the press or the like.

15. A feeder comprising a belt conveyor, means for applying vacuum to maintain sheets or the like against the belt conveyor, said means being so constructed and arranged as to apply the vacuum to sheets disposed against the belt conveyor only in the zone of the longitudinal center line of the sheets and means for advancing the belt conveyor.

16. A feeder comprising a carrier, means for applying vacuum to maintain sheets or the like against the carrier, said means being so constructed and arranged as to apply the vacuum adjacent the forward edges of sheets disposed against the carrier, guide means against which the forward edges of the sheets are adapted to be registered and means for advancing the carrier to register the sheets against the guide means.

and advance it to said belt,

ing it into contact with said belt out of contact with any other sheet.

advanced by said first mentioned means.

19. Sheet handling mechanism comprising a movable surface against which sheets being advanced are adapted to lie, pneumatic means for holding sheets against said surface and means for disposing sheets in overlapped relationship to be advanced while held against said surface.

20. Sheet handling mechanism comprising a perforated endless conveyor element, suction means operable through the perforations in said conveyor element to hold sheets in place thereon and means for disposing sheets in overlapped relationship upon said conveyor element.

21. Sheet handling mechanism comprising a constantly moving alternately accelerated and decelerated sheet conveying element, means for disposing sheets in overlapped relationship upon said conveying element and pneumatic means for holding said sheets thereon.

22. A method of handling sheets comprising disposing the same in overlapped relationship upon a movable sheet conveying element, maintaining the sheets in place on said element pneumatically and moving said element with the sheets so maintained in place thereon to advance the same.

23. A method of handling sheets comprising disposing the same in overlapped relationship upon a movable sheet conveying element, maintaining the sheets in place on said element pneumatically and advancing said element with an uninterrupted though alternately accelerated and decelerated feeding movement with the sheets so maintained in place thereon.

24. Apparatus for successively conveying sheets from a pile thereof to a-processing machine such as a press comprising a traction belt, and means for separating a sheet from a pile thereof and causing it to engage said belt, means for driving said belt at a variable speed whereby a sheet engaging the belt is decelerated and moved slowly toward said machine, means opposed to the belt moving toward said machine at variable speed synchronously with said belt for insuring continued engagement between the sheet and belt, and means for arresting the sheet in a predetermined position relative to said machine.

25. Apparatus for conveying sheets singly from a pile thereof to the cylinder of a press comprising a belt conveyor, suction means for maintaining sheets on said belt conveyor during movement thereof and a member adjacent the rear of said pile for separating the uppermost sheet therefrom and carrying it forward to a position in which it overlies said belt conveyor sufficiently that upon release of the sheet by said member the sheet will be maintained on said belt conveyor by said suction means and advanced with said belt conveyor.

' 26. In the art of feeding articles, taking an article from rest by suction means, delivering such article to a moving conveyor belt and thereafter changing the speed of movement of said belt and feeding the article from said belt to mechanism for operating upon the same at a speed difierent from the speed of movement of said belt at the time of delivering of the article thereto.

SAMUEL A. HUFFMAN. 

